Meteorite mineral named after beer is time capsule

TAKE a deep breath. Can you taste the flavour of ancient space? Nitrogen in Earth’s atmosphere has been traced back to the spinning disc of dust and gas that formed our solar system, and may even have yielded ammonia to fuel organic reactions. This all comes courtesy of a meteorite found in Antarctica named after a popular brand of beer.

“Our [meteorite] samples were collected in Antarctica in the late 1970s,” says Dennis Harries of Friedrich-Schiller University in Jena, Germany. “They fell there hundreds or thousands of years ago.” Known as chondritic meteorites, their history goes back some 4.6 billion years. At that time, our solar system was a vast disc of dust and gas, called the protoplanetary disc, spinning around the sun.

Harries and his colleagues were studying the make-up of the meteorites when they found a mineral called carlsbergite, named after the Carlsberg Foundation, an offshoot of the Danish brewery, which funded previous work on it.

Carlsbergite is a rare composite of chromium and nitrogen. Looking at the ratio of stable and unstable isotopes in the nitrogen, Harries found that it was very close to the ratio in the nitrogen that makes up three-quarters of Earth’s atmosphere today. That suggests they have a common origin, and the nitrogen in our atmosphere came from the protoplanetary disc.

Knowing the molecular composition of a given element at the time Earth was formed matters, says Louis Le Sergeant d’Hendecourt of the University of Paris-South, France. Nitrogen, for instance, can come as pure nitrogen gas or as ammonia, which also contains hydrogen. “This makes a hell of a difference, particularly if you are interested in prebiotic molecules like amino acids,” he says.

This makes a hell of a difference, particularly if you are interested in prebiotic molecules

Pure nitrogen is stable and unreactive, so an unlikely source for organic molecules, but ammonia can easily react to help form the organic chemistry that underpins life. So discovering that it was present even before our planet was formed may tell us something about the origins of life – although whether it helped trigger the formation of prebiotic molecules is still complete speculation.

“The presence of ammonia could have acted as an active ingredient in some of the chemistry needed to eventually get to life,” says Hope Ishii of the University of Hawaii at Manoa. “But it’s still a long way between having ammonia and having life.”

What about nitrogen compounds elsewhere in our solar system? “It seems possible that ammonia and organic molecules were brought to other bodies like Mars and Europa,” Harries says.

This article appeared in print under the headline “Meteorite named after beer acts as time capsule”